Answer:
There are 81 numbers
Step-by-step explanation:
Imagine that you have 4 boxes (one for each digit). In each box, you only have 3 choices for what digit you will do. You have to multiply all of the options (3*3*3*3) and you get 81.
More
Because the absence of corners allows more space for more balls
8(y+ 5) =3
1/3
7 x 3 = 21
21 / 3 = 7
The distributive property.